Abstract: A relatively simple, lighweight, portable, collapsible ladder includes a plurality of H-shaped sections pivotally interconnected end-to-end to define a flat bundle in the stored or non-use condition. The sections can be unfolded to a flat, extended conditions. In the extended condition, torsion springs cause the sides of the sections to fold inwardly to define side bars having U-shaped cross sections. By reversing the process, the ladder can readily be restored to the folded, storage condition.